make FFTALGO default, add MPI initialization, move allocation of sumsquare pointer to precalculate function

adept new reading scheme for MRC files to work with dynamic map memory allocation introduced in parallel git branch

fix bug in gpu fft code, index calculation was wrong if number of maps was higher than number of maps per cufft call

Fix allocation of FFTW scratch space, move deallocation of memory allocated in configuration to cleanup function, get rid of MAX_ORIENT constant